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(python2.1-lib.info)StreamReader Objects

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StreamReader Objects
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The `StreamReader' class is a subclass of `Codec' and defines the
following methods which every stream reader must define in order to be
compatible to the Python codec registry.

`StreamReader(stream[, errors])'
     Constructor for a `StreamReader' instance.

     All stream readers must provide this constructor interface. They
     are free to add additional keyword arguments, but only the ones
     defined here are used by the Python codec registry.

     STREAM must be a file-like object open for reading (binary) data.

     The `StreamReader' may implement different error handling schemes
     by providing the ERRORS keyword argument. These parameters are
     defined:

        * `'strict'' Raise `ValueError' (or a subclass); this is the
          default.

        * `'ignore'' Ignore the character and continue with the next.

        * `'replace'' Replace with a suitable replacement character.

`read([size])'
     Decodes data from the stream and returns the resulting object.

     SIZE indicates the approximate maximum number of bytes to read
     from the stream for decoding purposes. The decoder can modify this
     setting as appropriate. The default value -1 indicates to read and
     decode as much as possible.  SIZE is intended to prevent having to
     decode huge files in one step.

     The method should use a greedy read strategy meaning that it should
     read as much data as is allowed within the definition of the
     encoding and the given size, e.g.  if optional encoding endings or
     state markers are available on the stream, these should be read
     too.

`readline([size])'
     Read one line from the input stream and return the decoded data.

     Note: Unlike the `readlines()' method, this method inherits the
     line breaking knowledge from the underlying stream's `readline()'
     method - there is currently no support for line breaking using the
     codec decoder due to lack of line buffering.  Sublcasses should
     however, if possible, try to implement this method using their own
     knowledge of line breaking.

     SIZE, if given, is passed as size argument to the stream's
     `readline()' method.

`readlines([sizehint])'
     Read all lines available on the input stream and return them as
     list of lines.

     Line breaks are implemented using the codec's decoder method and
     are included in the list entries.

     SIZEHINT, if given, is passed as SIZE argument to the stream's
     `read()' method.

`reset()'
     Resets the codec buffers used for keeping state.

     Note that no stream repositioning should take place.  This method
     is primarily intended to be able to recover from decoding errors.

In addition to the above methods, the `StreamReader' must also inherit
all other methods and attribute from the underlying stream.

The next two base classes are included for convenience. They are not
needed by the codec registry, but may provide useful in practice.